Abstract
Cytogenetic studies on lymph node and skin biopsy specimens and peripheral blood in 104 patients with peripheral T-cell lymphomas (PTL) were compared with histopathologic diagnoses made according to the updated Kiel classification. Low-grade lymphomas presented normal metaphases more frequently than high-grade ones (P < .0001). This difference remained significant if cases with greater than 10% and greater than 50% normal metaphases in unstimulated cultures and in cultures stimulated by different mitogens were compared. On the other hand, high-grade lymphomas more often showed aberrant clones (P < .05), triploid to tetraploid clones (P < .0001), and complex clones with more than four chromosome changes (P < .01). Low-grade PTL showed consistent cytogenetic features. Clones with both inv(14)(q11q32.1) and trisomy 8q, mostly caused by i(8q)(q10), were found in all cases of T-cell chronic lymphocytic leukemia (T-CLL) and T-cell prolymphocytic leukemia (T-PLL). Trisomy 3 was observed only in angioimmunoblastic lymphadenopathy with dysproteinemia (AILD)-type PTL, T-zone lymphoma, and lymphoepithelioid lymphoma. Moreover, the proportion of normal metaphases in these PTL was higher than in the other low-grade PTL (P < .01). On the contrary, T-CLL, T-PLL, and cutaneous T-cell lymphomas (CTCL) showed complex clones (P < .0001), duplications in 6p (P <.01), deletions in 6q (P < .01), trisomy 8q (P < .00001), inv(14) (P < .00001), and monosomy 13 or changes of 13q14 (P < .001) more frequently than the other low-grade PTL. Trisomy 5 and + X predominated in AILD- type PTL. A cytogenetic feature characteristic of AILD-type PTL and CTCL was unrelated clones, which were found in 15% of AILD-type PTL and 17% of CTCL. The only chromosome aberration restricted to a certain high-grade PTL was t(2;5)(p23;q35) in large-cell anaplastic lymphoma. Deletions in 6q, total or partial trisomies of 7q, and monosomy 13 or changes of 13q14 turned out to be significantly more frequent in high- grade than in low-grade lymphomas (P < .01, P < .01, and P < .05, respectively). In summary, the cytogenetic findings in our series of 104 PTL enabled us to distinguish not only between low-grade and high- grade lymphomas but also between various entities of PTL. Thus, the cytogenetic findings paralleled the histopathologic diagnoses made according to the updated Kiel classification.
Epidemiology, clinical and cytological features of lymphoma in Boxer dogs